Mineral oil composition



Patented June '19, 194% course stares MINERAL 01L CQSITIQN Herschel G. Smith, Wallingiord, and Troy L. fiantrell, Lansdowne, Pa., and

John G. Peters, Au-

dubon, N. J assignors to Gulf Oil Corporation, Pittsburgh, lPa., a corporation oi Pcnnsyisania No Drawing. Application December '2 Serial No. 566,4ib2

5 Claims.

improved oil compositions being useful-and ad-c vantageous in protecting metals, both ferrous and non-ferrous from rust, corrosion and wear.

It also includes methods of making such agentsand improved oil compositions containing the same.

As is well known, the simple, straight mineral oils usually are def cient, in one or more respects, for certain commercial uses and it is common practice to incorporate one or more "additive compounds in the oil to overcome the defect or defects thereof for certain uses. Likewise, various agents have been incorporated in oils, to improve certain of their properties for particular or special uses requiring a superior oil. In general, such agents or additive compounds are known as improvement agents.

We have now discovered certain new improve ment agents for mineral oils which are particularly advantageous in the commercial preparation of various lubricants, protective coating compositions and other useful mineral oil compositions, Our agents can be readily incorporated in various mineral'oils and oil compositions. When incorporated therein, even in very small amounts, these agents markedly improve the rust preventive qualities thereof. Further, they are also capable of imparting other useful and advantageous properties to mineral oils and oil compositions, as more fully described post.

Our new and advantageous improvement agents for mineral oils and oil compositions are (Gil . 252- 51) wherein R. represents an alkyl group containing 3 to carbon atoms. They are also known as aluminum N-alkyl amide hthalates. Genericak ly, these agents areneutral aluminum salts of N- alkyl amido phthalic acid, as shown in the above formula.

As a class these compounds are usually waxy solids at ordinary room temperature, i, e, F., but soften and melt at elevated temperatures;

they being viscous liquids at elevated temperatures below their decomposition point. They can be readily fluxed and blended with mineral oils.

" In fact they are sufilciently soluble in various mineral oils for the present purmdses; they being readily soluble in naphthenic type oils. On the other hand, they are water-resistant compounds which are practically insoluble in water and aqueous solutions. That is, they have a combination of properties which render them particularly advantagous for the purposes ofthis invention, as is shown more fully post.

These compounds or agents can be readily prepared from aluminum hydroxide, phthalio anhydride and primary alkyl amines, advantageously amines having the following generlciormula:

HzN-CHr-(CI-Iz) 1rCH3 wherein n is a number between 6 and'18.- Some of the amines. of this generic class are Mono-capryl amine Mono-lauryl amine Mono-myristyl amine Mono paImityl amine Mono-stearyl amine and other primary alkyl amines having the above formula. Any of the above amines may be used with advantage in making ourgagents. For in-' stance, mono=stearyl amine (primary octadecyl amine) may be used to prepare agents which are advantageous for certain purposes. Further, mixtures of such amines may also be employed; somewhat better products being obtained with mixed amines. commercially available mixture of such amines is the so-called cocoamine" prepared 'byconverting the mixed acids of cocoanut oil into corresponding amines by well known methods. The

commercial "cocoamine has an average molecu-' lar weight of about -210, and may be employed with advantage in preparing our improvement agents.

In preparing our agents from these primary alkyl amines, phthalic'anhydride and aluminum hydroxide are reacted together and converted into new compounds; they being chemically combined together in the molecular ratios necessary to produce new compounds having the,generic structure given ante. in doing so, we usually For instance, one

react the primary alkyl amine with phthalic anhydride in substantially equimolecular amounts to form a mono-alkyl amide of phthalic acid, and then neutralize the residual acidity of that compound by reaction with aluminum hydroxide, suiiicient aluminum hydroxide being employed to form substantially neutral aluminum salts thereof. These reactions can be advantageously.effected in the presence of sufiicient mineral oil to dissolve the oil-soluble compounds so obtained; the new improvement agents being formed in situ in the .oil.

The improvement agents so prepared are advantageous for the present purposes. These advantageous agents are oil-soluble compounds having the following formula:

H u HzC-(CHrM-CHa-JiI-j o Gr w- G O O a wherein'n is a number between 6 and 18. This class of agents, prepared from said amines, are particularly advantageous in the practice ofthis invention.

The following examples illustrate various methods of preparing our improvement agents and improved oil compositions containing the same.

Example I.--In this example, the improvement agent was prepared in situ in-mineral oil from phthalic anhydride, dodecylamine and aluminum hydroxide; the agent so prepared being an aluminum phthalyl dodecylamide compound having the following formula:

H genteel-(crimson;

The procedure employed in preparing this compound was as follows:

Into an iron vessel equipped with means for heating, stirring and cooling, were charged 444 pounds of phthalic anhydride to ,which 555 pounds of dodecylamine were slowly added. To this mixture were added 2000 pounds of '70 viscosity at 100 F. Texas oil and the components were thoroughly agitated and slowly heated to 120.F. After one hour 435 pounds of alumina (gelatinous 18% A1(OH)3), Aluminum Ore Company, Pittsburgh, Pennsylvania, were added and the mixture was kept at 140 F. until the formation of water was completed and no more water could be drawn oil.

From the kettle 2966 pounds of aluminum phthalyl dodecylg amide oil mixture were obtained. In thi particular example 411 pounds of water were obtained and the loss for this whole process was only 57 pounds or 1.7% by weight.

The aluminum phthalyl dodecyl amide produced in situ in oil had the following properties:

Gravity: API 20.8 Viscosity, SUV:

210 F. Neutralization No Ash assulfate: percent:

Method 408, Gulf 5.6

This improvement agent had a good color and was substantially freeof insoluble. matter; it being a concentrated solution of the aluminum phthalyl dodecyl amide in the oil. It was readily miscible with various mineral oils and oil compositions and was directly soluble in most mineral oils in amounts efiective for the present purposes. In particular, this improvement agent is useful and advantageous as an additive compound in preparing improved motor oils and light lubricants. It is also advantageous in preparing other improved oil compositions useful in protecting metals against abrasion and corrosion. That is, the foregoing example is typical and illustrative of certain embodiments of this invention. In other embodiments thereof, other primary alkyl amines can also be employed in making our improvement agents, as stated ante.

In fact, by the present invention a. wide range of improvement agents can be readily prepared in the generic practice of this invention. All of them are readily soluble in commercial mineral oils and oil compositions in the proportions required to effect the desired improvements. Indeed, a wide range of improved anti-rust lubricents can be prepared readily by incorporating minor amounts of our improvement agents in suitable oils and oil compositions. In general, such improved anti-rust lubricants effectively protect ferrous and non-ferrous metals against rusting and corrosion, even when exposed to salt water and other severe service conditions.

For instance, advantageous anti-rust lubricants can be prepared by dissolving in light lubricating oils small amounts of the product obtained in Example I. The following example is typical and illustrative of such improved lubricants obtainable by the present invention.

Example H.One such advantageous anti-rust lubricant containing 0.3% of aluminum phthalyl dodecyl amide compound (Example I) dissolved in a light lubricating oil (mechanism oil) effectively protected steel strips when subjected to a drastic salt water corrosion test. The properties of this improved oil and. the tests thereon are as follows:' Make-up: per cent by weight:

Mechanism 'oil 99.7

Inhibitor (Ex. 1) 0.3 Properties:

Gravity: API 30.0

Sp. G12, 60/60 F 0.8762

Lb./Gal., 60 F 7.296 Viscosity, SUV:

210 F 38.7 Neutralization No 0.06 Ash as sulfate: per cent 0.02 Corrosion Test:

Method 412, Gulf 4 cc. distilled water, 36 cc. oil, 12 days:

Steel strip; Appearance Bright I Area. rusted: per cent.........;.........

advantageous properties.

As can be readily seen from the above data. this inhibitor eilected a marked improvement in the anti-corrosive properties of this oil.

The said corrosion tests employed were standard tests for determining the rust-preventive properties of our non-corrosive oils. In such test the procedure is as follows:

Thirty-six cc. of the oil to be tested and 4. cc. of distilled water are placed in a 1" by 6" Pyrex test tube, a polished steel strip is inserted in. the oil-water mixture, and 2000 cc. of humid air per hour are bubbled through the mixture from a point near the bottom of the tube, so as to pro .vide aeration and mixing oi! the oil and water;

.level in the tube maintained byadditions of fresh water every 24 hours. This test is continued im- 12 days after which the test strip is removed and inspected.

A like test is also employed, for which straight sea water (or synthetic sea water) is used instead of distilled water. This variation is a for more severe corrosion test, the corrosion eiiects being usualy ten or more times those for iresh water, other testing conditions being the'same.

As shown by the test data ante, our improved anti-rust .oil had outstanding rust-preventive properties and satisfactorily passed said test, particularly the drastic test with sea water.

In view of their outstanding anti-rust properties and other advantageous properties shown ante, our improvement agents are useful and e vantageous in a wide range of commercial oil compositions. They may also be incorporated in minor amounts in other types oi oils, such as turbine oils, instrument oils, electric motor oils and other high quality lubricants where it is im portant to protect metal surfaces from mist and corrosion, as well as adequate lubrication thereof under service conditions. For example, improved turbine oilscan be readily prepared by dissolving 0.03 to 3.0% of our improvement agents in any of the commercial turbine oils.

Further, our new agents are also useful and advantageous in preparing improved motor oils. For lubricating automotive, aviation and Diesel engines, such improved motor oils can be readily prepared by incorporating a. few per cent of these improvement agents in a suitable mineral iubri eating oil. The compounded oils so obtained have improved detergent properties as Well as other advantageous properties. in general, such improved motor 0113 containing minor amounts of our improvement agents have a plurality oi In addition to protecthis metals from rust and corrosion, they have superior lubricating properties, even under severe operating conditions.

In particular, this invention relates to improved lubricating oils containing a multi-tuncticnal improvement agent having anti-oxidant and other advantageous properties such as high film strength. Moreover, the lubricating oils to which .1

our inhibitor is added are capable of retarding the-formation oi. all forms of gum, resins, carbon, and varnish-like materials which are, usually formed on the-pistons and rings internal combustion engines. In addition to the property of against corrosion tendencies. That is, our img and advantageous amount of such improvement agent being sumciproved lubricating compositions comprising a major amount 0! a petroleum lubricating oil and a minor amount oi. aluminum tri-phthalyl fatty amide compounds have improved detergent, antioxidant and other advantageous properties.

That is, our new improvement agents impart to mineral oil compositions a plurality of advantageous properties which render them'particularlyadvantageous for such purposes. For instance, these improved oil compositions tightly adhere to the metal, forming protective films thereon which are substantially impervious to water and aqueous solutions and which are resistant to removal from the metal even when vigorously agitated with aqueous liquids. ,That is, our improved oil compositions are markedly resistant to water and aqueous solutions, as well as stable against oxidat on.

Accordingly, in the broad, practice of this invention, a wide range of improved mineral oil compositions can be readily prepared, including excellent protective coating compositions, as well as improved onthrust lubricants. Thus, broadly, this invention relates to improved mineral oil compositions containing minor amounts of aluminum phthalyl alizyl amide compounds as a. new improvement agent; the

out to impart thereto the advantageous properties desired. In general, our improved oil composltionsusually'contain from 0.002 to 10.0% by weight oi such improvement agents dissolved in the mineral oil.

This application is a continuation-impart of our prior, copending application Serial No. 516,-- 968, died January i, was. In that application, we have described and claimed improved mineral oil compositions containing oil-soluble calcium phthalyl allryl amide compounds as an improvement agent. Further, as described in that application, those improvement agents are produced from the reaction. or interaction of calcium hydroxide, phthaiic anhydride and primary alkyi amines, under conditions fully describ d therein. Further, as stated in that appllcatioilwe have found that aluminum hydroxide may be used in lieu of lime in said reactions to produce aluminum phthclyl allay! amide compounds which are also useful as improvement agents in mineral oils and oil "compositions. The present application is directed to improved mineral oil compositions eontsining oil-soluble aluminum phthalyl alkyl amide compounds, advantageously those prepared by the methods-described in our prior application.

What we claim is:

1. An improved oil composition comprising a major amount of a mineral oil and a minor amount of an oil-soluble aluminum phthalyl allzyl amide compound having the following formula;

8 to 20 carbon atoms, the amount of said aluminum phthalyl alkyl amide compound being sufficient to impart corrosion inhibiting properties to the improved composition.

I 2. The composition of claim 1 wherein the said improved mineral oil composition contains from 0.002 to 10.0% by weight of said improvement agent dissolved in the mineral oil.

3. The improved composition of claim 1 wherein the said Oil-soluble improvement agent is aluminum tri-phthalyi dodecyiamide.

4. The composition of claim 1 wherein said improvement agent is an oil-soluble, substantially neutral aluminum salt of a mono-aikyl amide of phthalic acid.

5. An improved mineral oil composition comprising a major amount of a mineral lubricating oil containing dissolved therein from 0.002 to assesses wherein 'n is a. number between 6 and; 18, said improvement agent being substantially neutral and 15 readily soluble in mineral oiis.

HERSCHEL G. SWTH. TROY L. CAN'I'RELL.

JOHN G. PETERS. 

